How Bats Avoid Hitting Obstacles With Echolocation

Bats fly through complete darkness without bumping into cave walls or other obstacles. While researchers know they use echolocation to get around, how exactly they forge clear paths through complicated environments like caves and forests hasn’t been well understood. A new study by scientists at the University of Antwerp and the University of Bristol finds that bats navigate in the dark using a fairly simple mechanism. Writing in journal PLOS Computational Biology, they report that bats merely listen for the largest echo, and turn away from it. 

The paper argues that it would be practically impossible for bats to interpret all the echoes coming from numerous obstacles in cluttered spaces. To find an alternative explanation, the researchers used 2D and 3D models of simulated bat behavior in real forests and other complicated spaces. They hypothesize that rather than creating a 3D reconstruction of the environment using echolocation, bats rely on a quicker method of finding their way. They compare the volume of echoes in their right and left ears, and turn away from the louder echo, since that obstacle would presumably be nearer. They found that in the virtual model, this method allowed bats to avoid obstacles using just the first millisecond of the echo as a signal.

Since this is only a computational model of bat behavior, it will no doubt need to be further confirmed by experiments with actual bats.

Fascinated by echolocation? Bats can also use it to interfere with each other’s signals when competing for food.